In recent years, a stereoscopic vision technology has been widely applied in the fields such as mobile robot navigation, smart car navigation, three-dimensional reconstruction and precision measurement, and it is the most important distance sensing technology in a computer passive ranging method. A basic principle of stereoscopic vision ranging is to observe the same object at two viewing points so as to obtain perceived images from different viewing angles, and then a position deviation (i.e. a parallax) between pixels of the images is calculated based on a triangulation principle in order to obtain distance information of the object.
In the stereoscopic vision ranging technology, a dual-camera based binocular stereoscopic vision ranging technology is a key technology, which determines positions of the same object on two different imaging pictures by using dual cameras, so as to obtain a distance of the object.
For the binocular stereoscopic vision ranging, a depth is calculated based on a depth of field, and the farther the object, the lower the resolution. FIG. 1 shows a relationship between an identification distance and a ranging accuracy of a binocular stereoscopic vision device (with a binocular distance of 12 cm), wherein a horizontal axis represents a distance between a camera and an object, and a vertical axis represents a distance represented by unit data (for example, 1) under the distance. As shown in FIG. 1, the larger the distance between the camera and the object, the larger the distance represented by the unit data, that is, the lower the ranging accuracy. In practice, in order to improve a distant ranging accuracy, it is usually necessary to increase the distance between the two cameras; however, the larger the distance between the two cameras, the greater a space occupied by the binocular ranging device, which inevitably increases a volume of a terminal apparatus accommodating the binocular ranging device, and is disadvantageous to obtain a miniaturized and ultra-thin terminal apparatus.